/**
 * 懒加载
 * @author Tyr
 * @param {*}  
 * @return undefined
 */
 function lazyload(){
  var ckObj=window.innerHeight || document.documentElement.clientHeight
  var gdObj=document.body.scrollTop || document.documentElement.scrollTop
  var temp=ckObj+gdObj
  var imgObj=document.querySelectorAll("img")
  imgObj.forEach(function(item){
      if (item.offsetTop<temp){
          item.src=item.getAttribute("data")
      }  
  })
}
